Certificate of correction



Patented Aug. 9,21932 No Diawing.

f Vrliis invention Y relatesltoafprocessf fon theV production 4of diazo-nl'troaryl compounds and A more particularly to itliej'pi'odiietion'-- of pam-di-azo-nitrobenzene;

5. t is an object of the invention to=providepense of productionodinzomitroaicyl f compounds `is reduced'. f h V Another ob `ect of thel invention 1s to-pnovide a processinnccordance with the?opera` f5 tions oit-Which there 1s effectednisavingin materials and in which Various steps 1lieietofore consldeied` as necessaify'lialvebeen elim` inated. Fuithen there islipiovidedet p1 0'cess capable of' satisfactory commercial Y opeiahv 'A tion.

after.

, The `invention accordingly coinpiises'j'theA several 'steps Aof* the process andthe 'relation of one or more of suoli-` 'st'eps' with respect toY each ofthe' others"tlieifeoi?,` and will loe'exremV pliied in the kprocess heeinztfterdisclose@V and the'scope ofi the inVention'Willbe-indi-` Y l Y otherpi'ocedres inwvleiolnitsuseastinimy Si? cated Vin theol-aims.

c amine, then. to `isolate the aeylated 'niti'oj-i 35 arylztniine thus" produced"4 as" the nnztiiif prod"-V uctf of the lreaction andtlierlto split offtlie acyl group and isolate from the reaction'mixf ture the j nitroarylamine 'jso pi'odufcedfandf finally to edis'solve and vdizrzotize= itllen'itijoiV 40` arlyamine. f Y i Y I In the practice" of the present]invention7 an 'N-acylated 'nitroarylemineis" saponifiedin the presence ofamineral acid; andthe nitro-f v arylzunine thus roduced,` LWithout 4isolation *5 from thefsaponi cation 1nf 1ss','is"diazotizedto forniti diazo-nitroaryl compound'bysubjecting theV reaction mass tol th'eacti-on ofa-nii'- trate, the diazotization being l' cari-"ied'outf t prefeiablyduring'orafterf the dilution-lof 59' reaction mass or the-nitrite;orv1both5lwtli Otherl objects of the inventionf'will in peut`l` be obvious and Wille'inpartijappearfbereiirVV v complete-the acebvanldeshoul" 'Appnezatihnleegnugesi 24, i929.' fserialimi.381x268;r` f

.trated Rrefernbly with a mixed nitrating acid-i containing-2nitricfandsul'fni'ic acids,ethefstil-r furio'Aacidfbeingpresent'iiran aniount prefer# ably" greater# than that -Whichf isfequired 'fon edv ini the f' hetnet,

primary l:nitroenninov :compound -ifre's'ult'ing y from; the -sap oniication is y dizotizedflwitliontf f isolti on fonr the reaction 1 mess byi treltingl ci obtained isy siiitable-ndlwell adapted forlli'sew 236 `{mit-ts lof mixed nitrati jacid-inf the; same Eollowing nit'nation, them-ess c f inoveztherncetyl gronp,x-is lieettedfto29024115".V

C. for a period of several hours, or until a test portion of 15 drops in 5 cc. ofrwatergives a clear diazo solution when sodium nitrite is added. If a curdy precipitate appears in Vthis test, it indicates that saponiflca'tion ofr the acetyl group andA its replacement byl hydrogen isnot completed, inwhich case heating is continued a While longer. When the saponification is complete, the'solution iscool'ed and then is ready forv diazotization.v Y,

This. solution is added, and alsollOparts sodium nitrite are added, each separately and by stages to amixture of 2800 parts icej and 110.5parts of surfuriciacid, 5.0i B. A.A

vigorous agitation Vand an excess of nitrous acid. are maintained throughoutthe period of addition.A Whenlthe additions are complete, thevdiazo solution is stirred for awhile.

longer, e. g., about one hour.-y It shouldA give a faint testV for nitrous acid.V During diazotization, the temperature 'is lieptlow, e.. g.,

0`5 C.- The resulting solution of p-diaxo# nitrobenzene maybe coupledvvith suitable in-' ing until it becomes clear or until saponifica-v tion; is complete. Whencthe saponication iscomplete the solutionisjcooled and is theny diazotizedV as described in Example 41,us1`ng c a corresponding proportion of sodium nitrite and other reagents and ingredients.

It Will befunderstood that the invention inV fitsvbroad aspect isnot limitedlto thecompounds and specific; conditions asset forth in the examples hereinbefore .given but that it may be utilized forV the YproductionV of diazonitroaryl compounds other vthan diazo-nitrobenzene and that the aminogroup, during the nitrating period, may be protectedby otherV acyl ,groups than the acetyl group.; Accord; ingly, 1in place of acetanilide there may be.

used ythe a'cyl derivatives of vits homologues and, further, the'alkyl ethers'of acetanilide and of 'its homologues may be used.V It is desired further to indicate thatthe-inven- 'tion is not limited tothe particular method of nitration above described' for the reason that other methods of nitration'may be em-' ployed to -introducethe nitro groupnan'df When such other method of ,nitratio-nfis emA i ployed then the acyl group may be'split od by heating the resulting nitrationreaction mass with the addition of aymineral 4acid, as

sulfuric acid, and hydrochloric acid inthe event that an acid suchuassulfuric acidv has not been used yin suii'icient quantity during the nitration period-j c A By proceeding inaccordance with the foregoing methoda marked saving in vmaterialsV may. be effected, as Well as a marked saving.

3. A process for the production precipitating the nitro-arylamine andfiltering it, and finally dissolving it in acid for diazotization when it -Was desired to proceed With the acylated nitro-arylamine as the starting' materialfor effect-ing theproductiony of thediazo compound. j

l Since certainchanges may be made in carrying out the above process Without departing from. the scope. of the' invention, it is intended'that all'mattercontained in the above descriptionshall be interpreted as illustrative and not ina limiting sense. y v

y Having described my invention, what AI claim as new and desire toisecu'r'e by Letters Patent-is;V pl. A process for, the production of diazof nitroaryl compounds which comprises nitrating an'acylatedarylamine to form a nitroacylarylamine, heating the vresulting nitroacylarylamine, Without isolation from theyreaction mass,in,the presence ofmineral acid Y to split off they acyl group, and then diazotizing the resulting,nitroarylamine'Without isolation from the resultingmixture.

.2. A process for the production of dia-zonitroaryl compounds VWhich ,comprises nitratingran acylated arylainine lin the presence of sulfuric acid, heating the AAresulting reaction mass With the production` of anitro-arylamine, and then causing that resulting reaction mass to react With ra nitrate to produce a diazo-nitroarylcompound. l' Y l I of a diazonitroaryl compounds Which comprises nitrating an acylatedarylaminein the presence -of sulfuric acid in an amount greater than that required for nit-ratiomheating the resultingA reaction mass with theproduction of a nitro arylamine, andthen V'causing Vthat resulting reaction mass to react Ywith a nitrite tok produce a diazo-nitroarylcompound. f Y' j 4. A process for the production of diazo- Y nitrobenzeney Awhich comprises nitrating an acylaniline With a mixture of nitric and sulfuric acids to` form the acylnitroaniline,then

Vheating the acyl-nitroaniline, vvithoutdisola-l tion thereoffrom the reaction mass, to form nitroaniline, and then admixing the resulting reactionmass .vwithrsodium nitrite with the production of diazo-nitrobenzene.. 5. 5,--A process .for the production ofdiazonitrobenzene which comprises nitrating acetanilide With a mixture of -nitric 'and sulfuric vacids ata temperature of 25 tol 30 C; to

form nitro-acetanilide, then heating .the nitro-acetanilide, Without isolation from the resulting reactionfmass, with the, formation" of p-nitraniline, vand then diazotizingfthe -p-nitraniline' Without isolation Vfrom the reac-V tionfmass thus obtained: Y

6. A process for the production of diazonitrobenzene which comprises nitrating acetanilide at a temperature of 25 to 30 C. with a mixture of nitric and sulfuric acids to form nitro-acetanilide, the sulfuric acid being in an amount greater than that required for nitration, then heating the nitro-acetanilide without isolation from the resulting reaction mass, with the formation of p-nitraniline, and then diazotizing the p-nitraniline Without isolation from the reaction mass thus obtained.

7. A process for the production of diazonitrobenzene Which ycomprises nitrating acetanilide at a temperature of 25 to 30 C. with a mixture of nitric and sulfuric acids to form nitro-acetanilide, the surfuric acid being in an amount greater than that required for nitration, then heating the nitro-acetanilide, Without isolation from the resulting reaction mass, with the formation of p-nitraniline, and then diazotizing the p-nitraniline Without isolation from the reaction mass thus obtained, by adding the cooled reaction mass and. sodium nitrite separately and by stages to a mixture of ice and sulfuric acid.

8. A process for the production of a diazonitroaryl compound which comprises treating a nitro acylarylamine with a mineral acid to saponify o the acyl group, and Without isolation from the resulting solution, diazotizing the nitro-arylamine thus produced.

9. A process for the production of a diazonitroaryl compound which comprises treating a nitro-acetylarylamine with a mineral acid to saponify'o the acetyl group, and Without isolation from the resulting solution, diazotizing the nitroarylamine thus produced.

10. A process for the production of a diazo-nitrophenyl compoun which comprises treating a nitro-acylphenylamine With a mineral acid to saponify oif the acyl group, and Without isolation from the resulting reaction liquor, diazotizing the nitro-phenylamine thus produced.

11. A process for the production of a diazo-nitro-phenyl compound which comprises treating a nitro-acetylphenylarnine With'a mineral acid to saponify off the acetyl group, and Without isolation from the resulting reaction liquor, diazotizing the nitrophenylamine thus produced.

12. A process for the production of diazonitrobenzenel which comprises treating nitroacylanilide With a mineral acid to saponify oif the acyl group, and Without isolation Jfrom the resulting reaction liquor, diazotizing the nitroaniline thus produced.

13. A process for the production of diazonitrobenzene which comprises heating-nitroacetanilide with a mineral acid to saponify off the acetyl group, and Without isolation from the resulting solution, diazotizing the nitraniline thus produced.

14. A process for the production of diazoacetanilide With sulfuric acid to saponify,

olf the acetyl group, and Without isolation from the resulting solution, dia-Zotizing the nitraniline thus produced.

15. A process for the production of a diazonitroaryl compound which comprises treating an acylated nitroarylamine With a mineral acid to saponify 0H the acyl group and then adding sodium nitrite and the reaction mass separately to a mixture of ice a-nd a mineral acid. l

16. A process for the production of a diaZonitrophenyl compound Which comprises treating an acylated nitrophenylamine with a mineral acid to saponify oif the acyl group and then adding sodium nitrite and the reaction mass vseparately and by stages to a mixture of ice and a mineral acid.

17. A process for the production of a diazonitrobenzene which comprises treating nitro 1 acetanilide With a mineral acid to saponify off the acetyl group, and then adding sodium nitrite and the reaction mass separately and by'dstages to a mixture of ice and mineral aci 18. A process for the production of diazonitrobenzene which comprises-treating nitro acetanilide With sulfuric acid to saponify off the acetyl group, and then adding sodium nitrite and the reaction mass separately and by stages to a mixture of ice and sulfuric acid, While maintaining an excess of nitrous acid.

19. A process for the production of diazonitrobenzene Which comprises nitrating acetanilide at a temperature of 25 to 30 C. with a mixture of nitric and sulfuric acids to form nitro-acetanilide,fthe sulfuric acid being inv an amount greater than that re-- quired for nitration, then heating the nitroacetanilide, Without isolation from the resulting reaction mass, with the formation of p-nitraniline, and then diazotizing the pnitraniline, Without separation from the mass thus obtained, by adding the cooled lreaction mass and sodium nitrite separately and by stages to a mixture of ice and sulfuric acid While maintaining agitation andv an excess of nitrous acid throughout the period of addition.

In Witness whereof, I have hereunto set my hand.

LAWRENCE H. FLETT.

' iso CERTIFICATE 0F CORRECTICN.

Patent No. 1,870, 842. August 9, 1932.

LAWRENCE H. FLETT.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, line 48, for the syllable "trate" read trite; page 2, line 101, claim 2, for "nitrate" read nitrite; and that the said Letters Patent should be read lwith these corrections therein that the same may conform to the record of the caste in the Patent 0ffice.

Signed and sealed this 22nd day of November, A. D. 1932.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

